Those disorganized white blobs? Lightning strikes! And if you look closely, you can even see tracks from meteors and satellites. Christoph Malin, who created the video, explains:

This video was achieved by "stacking" image sequences provided by NASA from the Crew at International Space Station. These Stacks create the Star Trails, but furthermore make interesting patterns visible. For example lightning corridors within clouds, but they also show occasional satellite tracks (or Iridium Flashes) as well as meteors - patterns that interrupt the main Star Trails, and thus are immediately visible.

One thing's certain: thunderstorms sure look prettier from space than they do from the ground. [Vimeo]